Northern Clingfish, Gobiesox maeandricus

Northern Clingfish, Gobiesox maeandricus. Fish caught from a tidal pool in coastal waters of Monterey, California, March 2021 via micro fishing with size 30 Tanago hooks. Length: 3.8 cm (1.5 inches). Catch, photograph and identification courtesy of Chris Moore, Peoria, Arizona.

Northern Clingfish, Gobiesox maeandricus. Fish caught from a tidal pool in coastal waters of Vancouver, British Columbia, Canada, July 2018. Length: 10.2 cm (4.0 inches). Catch, photograph and identification courtesy of Eli (obsessiveangling.wordpress.com).

Northern Clingfish, Gobiesox maeandricus. Fish caught from a tidal pool in coastal waters of Sidney, British Columbia, Canada, August 2021. Length: 10.2 cm (4.0 inches). Catch, photograph and identification courtesy of of George Brinkman, Guelph, Ontario, Canada.

The Northern Clingfish, Gobiesox rhessodon, is a member of the Clingfish or Gobiesocidae Family, and is known in Mexico as chupapiedras norteña. Globally, there are twenty-nine species in the genus Gobiesox, of which seven are found in Mexican waters, one in the Atlantic Ocean and five in the Pacific Ocean and one, this species, in both the Atlantic and Pacific Oceans.

The Northern Clingfish has an elongated “tadpole” like body that are tallest and widest at the pectoral fins. They are a light olive brown to cherry red color with reticulated darker or mottled light shades and dark radiating lines from the eyes. They have white bars between the eyes; the juveniles also have white bars across the back and at the margin of the caudal fin. Their head is very large and very flattened and broader than the body but not as deep and is located at the front and is equipped with chisel-like teeth. Their anal fin has no spines and 12 or 14 rays; their caudal fin is rounded; their dorsal fin has no spines and 13 to 16 rays; their pectoral fins have 21 to 23 rays and are short and broad and form a large adhesive disk on the underside; and, their pelvic fins are fused. The sucker on their ventral side is disproportionately large. Their skin is smooth. They do not have scales.

The Northern Clingfish is a shallow-water solitary non-migratory species that are found at depths up to 12 m (35 feet) within intertidal rocky areas clinging to the underside of small rocks within tidal pools among algae and kelp exposed to high surf in very hostile environments. They reach a maximum of 16 cm (6.3 inches) in length. They have the ability to survive out of water for extended periods of time capable of breathing air. They feed primarily on small crustaceans, isopods, limpets and mollusks that they pry off the rocks. They are preyed upon by rockfishes, various sea birds and during low tide episodes by minks, racoons, snakes and other terrestrial animals. Reproduction is oviparous involves nest building by the males within rocks, the release of large amounts of eggs by the females which attach themselves under rocks are then fertilized by the males. The males guard the eggs and the planktonic larvae hatch which fairly move and attach themselves to kelp and with maturing move to the intertidal areas. The Northern Clingfish is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

The Northern Clingfish is a resident of Mexican waters of the Pacific but has a limited distribution being found within the coastal waters of the Revillagigedo Islands and from Guerrero Negro, Baja California, northward along the central and northwest coasts of the Baja.

The Northern Clingfish is straightforward to identify due to its coloration and markings, thus cannot be confused with any other species.

From a conservation perspective the Northern Clingfish has not been formally evaluated but they should be considered to be of Least Concern with stable widely distributed populations. Their long-term viability is threatened by pollution and human coastal developments. They are too small to be of interest to most. Their ability to cling to both rough and slimy surfaces under severe tidal flow conditions has drawn the interest of the scientific community. They can be found on a limited basis in public aquariums and sold by the aquarium trade. Surprising, they can also be caught by recreational hook and line fishermen.